Space
Euclid spots a new comet
A galaxy-mapping telescope found a moving visitor close to home.
THE JOURNAL
Questions worth following.
Explore science, history and everyday questions. Search the journal or follow a topic below.
All topicsMind & BehaviourSpaceEarth & OceansPhysics & Everyday ScienceTechnology & EngineeringLife & NatureMedicine & the BodyHistory & Discovery
LEARNING LAB · INTERACTIVE
The Periodic Landscape
Explore all 118 elements, rotate a 3D atom, look inside its nucleus and discover protons, neutrons and quarks. Start with the familiar table, then look closer one level at a time.
Explore the periodic tableFree to explore. Includes guided discoveries, comparison and a 2D alternative.
87 stories
Technology
A sleeve that works like a touchscreen
Researchers weave display and touch sensing into fibres, with everyday use still to be proven.
Earth
What storm waves do to a salt marsh
A marsh can keep its ground while damage to its plants weakens part of its wave protection.
Medicine & the Body
How bones renew themselves
A skeleton stays useful by replacing small patches. Cells remove old bone, other cells build a new protein framework, and mineral gradually hardens it.
Space
How starlight reveals what a star is made of
The dark lines in a star’s rainbow identify atoms. Working out how much of each element is there requires another clue: what heat has done to their electrons.
Nature
How an ice core traps pieces of ancient atmosphere
Snow leaves air connected to the sky. As burial closes those passages, ice seals atmospheric samples that scientists can recover much later.
Technology
How a hard drive writes and reads invisible magnetic bits
A hard drive turns current into a tiny magnetic pattern, preserves that pattern without power, then converts it back into an electrical signal as the disk spins.
History
How buried sand records time since daylight
Quartz grains can store a faint record of radiation received in darkness. Reading that signal can estimate when sediment was buried, provided sunlight really reset it and the dose history is known.
Mind & Behaviour
Why a smell can bring back a vivid memory
A familiar scent can revive a surprisingly personal scene. The explanation involves chemical signals, learned associations and connected brain networks, not a shortcut to a perfect recording.
Everyday Science
Why wet fabric looks darker
The dye need not change. Water alters the optical boundaries between fibres, so less light scatters straight back and more travels into the cloth where it can be absorbed.
Medicine & the Body
Why fingers wrinkle in water
The ridges are not simply waterlogged skin. An intact nerve pathway narrows blood vessels beneath the surface, changing the support under the fingertip skin.
Space
Why pulsars seem to blink
A pulsar does not simply switch on and off. Its rotation sweeps a directional pattern of radiation past Earth, turning geometry into a remarkably regular pulse.
Nature
Why some sand dunes sing
A dry avalanche can turn moving grains into a deep, sustained note. Experiments reveal parts of the process, while how the pitch is selected and natural booms are amplified remains disputed.
Technology
How a photocopier copies with light and static charge
A copier does not press ink against the original. It turns reflected light into a temporary electrical pattern, gives that pattern to toner, and then moves the toner onto a new sheet.
History
How a tooth can hold clues to where someone grew up
Tooth enamel preserves a childhood strontium ratio. Comparing it with environmental baselines can test local origins, but it cannot supply an exact address.
Mind & Behaviour
Why speech can sound whole when a sound is missing
A cough can conceal a missing speech sound so effectively that you hear a complete word. Experiments distinguish that perceptual completion from guessing, and from putting sound back into a recording.
Everyday Science
Why a fizzy drink starts bubbling when you open it
The gas was already there, dissolved in the liquid. Opening the bottle changes its equilibrium, but a bubble still needs a place to begin.
Medicine & the Body
Why bruises change colour as they heal
Escaped blood is dismantled, its pigments are chemically changed, and material is cleared or recycled. The colours reveal that cleanup, but not a reliable injury clock.
Space & Physics
How sunlight can push a spacecraft
Light carries momentum as well as energy. A large, lightweight mirror can turn that invisible delivery into a small push that keeps changing a spacecraft's motion.
Nature
How leaves pull water to the top of a tree
A tree has no heart pushing water upstairs. Evaporation in its leaves puts liquid water under tension, and a connected transport network carries the pull down to the roots.
Technology
How a quartz watch turns vibrations into seconds
A tiny crystal keeps a fast rhythm. Electronics count it down to a pace we can read, while a battery quietly supplies the energy.
History
How invisible volcanic ash links distant histories
A layer too sparse to see can connect a peat bog, a lake bed and an archaeological site. The link comes from volcanic glass, careful chemistry and disciplined doubt.
Mind & Behaviour
Why a song gets stuck in your head
A tune can return without an invitation. Experiments explain some of its entrances, but the repeating fragment still leaves scientists with a puzzle.
Medicine & the Body
Why swallowing helps your ears pop
A swallow briefly opens an air passage behind the nose. That lets pressure catch up on the far side of the eardrum.
Everyday Science
How soap helps water carry grease away
Soap changes what happens where water meets oil. Cleaning still needs movement, separation and a rinse that carries the loosened material away.
Space & Physics
How separated radio dishes act like one giant telescope
Distant antennas do not stitch photographs together. They compare carefully timed wave signals, using the spaces between dishes to measure finer detail.
Earth
How groundwater moves through solid-looking rock
Groundwater usually does not travel through hidden rivers. It follows connected pores and fractures, driven by differences in water level and pressure.
Technology
How e-ink keeps a page without power
An e-reader moves tiny pigment particles to change its page. Keeping that arrangement visible is a different job, and that difference explains both its efficiency and its compromises.
History
How light helps read writing that was erased
Reused manuscripts can retain traces of older ink. Different imaging methods measure different clues, which scholars must still interpret.
Mind & Behaviour
Why your own touch often feels less ticklish
A copy of a movement command helps the brain predict some of its sensory consequences. That explains muted self-touch, but not every mystery of tickling.
Medicine & Body
Why a cut stops bleeding before it heals
Platelets and a protein mesh make a temporary seal. Rebuilding living skin is a larger, overlapping job.
Everyday Science
Why a metal spoon feels colder than wood
Both can start at the same temperature. What your hand notices is how their surfaces exchange heat with your skin.
Space & Physics
Why astronauts float while gravity still pulls them down
The space station has not escaped Earth’s gravity. It stays aloft because gravity bends a fast sideways journey into a continuous fall around the planet.
History
How overlapping tree rings turn wood into a calendar
Matching growth patterns across living trees, old timbers and buried wood lets researchers build a calendar longer than any single tree’s life.
Earth
Why rivers make their own bends
A river bend is not merely a curve in the bank. The curve reorganises pressure, flow and sediment, then those changes move the curve itself.
Technology
How headphones make quiet by adding sound
Noise cancellation does not remove sound from the room. It adds a carefully timed counter-pressure near your ear, with performance that depends on the sound and the headphone design.
Nature
How a bat rewrites its question to the dark
A bat does not merely listen for echoes. It changes the timing, shape and aim of each call according to what the previous echo made worth asking next.
Mind & Behaviour
Why you cannot see the hole in your own vision
Every eye sends the brain an image with a piece missing. The missing piece does not look black because black would itself be information.
Medicine & the Body
How kidneys build a salt staircase to save water
The kidney does not simply squeeze water out of urine. It first writes a chemical gradient into its tissue, preserves that gradient, and opens microscopic doors only when water should follow.
Everyday Science
Why popcorn rebuilds itself during an explosion
One kernel performs four jobs in a fraction of a second: pressure vessel, breaking shell, steam engine and mould for a new edible foam.
Space
How four clocks turn time into a place
A GPS satellite does not watch your phone. It broadcasts a time, a position and a problem that your least trustworthy clock helps solve.
History
How a dying atom became archaeology's clock
Radiocarbon dating does not read a date stamped inside an object. It builds a probability from cosmic rays, living carbon, atomic counting, tree rings and archaeological context.
Nature
How roots find down in the dark
A root does not carry a compass. It divides the problem: cells in the tip detect a change, a moving hormone signal reports the error, and cells farther back perform the turn.
Engineering
Why the Tacoma Narrows Bridge twisted itself apart
The famous film looks like a story about wind pushing a bridge. The deeper lesson is stranger: motion changed the air, and the air fed energy back into the motion.
Climate
How scientists discovered the greenhouse effect
No one saw the whole mechanism at once. A planetary puzzle became a cylinder experiment, then a measurement of invisible radiation, then a calculation about climate.
Mind & Behaviour
Why attention can miss the obvious
A gorilla in a medical image puts three explanations on trial: poor visibility, lack of skill, and the gap between looking and noticing.
Weather
Why deserts can become cold at night
The ground does not wait until sunset to lose heat. Darkness changes the balance. Dry air, clouds, wind and stored warmth decide what happens next.
Medicine & the Body
How vaccination builds immune memory
A vaccine can leave the body better prepared long after its ingredients have gone. The lasting change is a population of cells and the responses they can make.
Oceans
How sea ice differs from an iceberg
Both float in the ocean, but one freezes there while the other arrives from land. Their different beginnings change their salt content, behaviour and place in the climate system.
Everyday Science
Why bread dough rises
A living fungus makes the gas, a protein-and-starch structure holds it, and heat turns a temporary foam into a loaf that keeps its shape.
Space
Why the Moon is slowly moving away
The Moon is not simply escaping. Ocean tides take a little spin from Earth and pass angular momentum into the lunar orbit, while laser echoes reveal the change centimetre by centimetre.
History
How photography learned to freeze light
Early cameras accumulated minutes of change. Faster chemistry, precise shutters and brilliant flashes turned an exposure into a measured slice of time.
Oceans
How scientists map a seafloor they cannot see
A depth map begins with an echo, but making it trustworthy requires clocks, water profiles, ship-motion corrections and an honest account of what remains unknown.
Technology
How barcodes turn stripes into error-checked numbers
A supermarket scanner joins optics, arithmetic and a shared naming system. Its smallest safeguard is one extra digit, and that digit has revealing limits.
Earth
Earth's magnetic field: a moving source beneath our feet
A compass appears calm, but its direction is maintained by turbulent, electrically conducting metal thousands of kilometres below. The result is always changing.
Medicine & the Body
How anaesthesia changed what surgery could attempt
Ether did more than remove pain. It separated the operation from the patient’s immediate struggle and created a new problem: how to control a reversible, risky physiological state.
Physics
How rainbows form: the geometry inside a raindrop
A rainbow is not painted onto the rain. It is a moving agreement between sunlight, spherical drops and one observer standing at the cone’s tip.
History
How patterns unlocked Linear B
Before anyone could read the words, Alice Kober found relationships between signs. Turning those relationships into Greek required careful records, risky guesses and tests that could fail.
Oceans
How rogue waves become unusually large
A North Sea measurement turned an extraordinary wave into evidence. Understanding it means looking at the surrounding sea, the timing of crests, and the limits of a forecast.
Everyday Science
How a refrigerator moves heat
The cabinet does not manufacture cold. A circulating fluid, a pressure change and a motor carry energy from the food compartment into the room.
History
How sailors learned to find longitude
A ship needed to know the time somewhere else. Making that possible took astronomers, stubborn clockmakers, human computers and years of testing.
Mind & Behaviour
Why memories can be unreliable
A vivid memory can feel like evidence. Experiments reveal why remembering an experience and judging its accuracy are different jobs.
Space
How auroras light Earth's upper atmosphere
A magnetic world, energetic electrons and a competition between light and collisions turn invisible space weather into curtains of colour.
Medicine & the Body
How penicillin became a medicine
A mouldy dish revealed a possibility. Turning it into a dependable treatment required a second story: patients, painstaking chemistry and the engineering of living factories.
Oceans
Why oceans look blue, green or brown
Ocean colour is a record of which wavelengths entered the water, which were absorbed, and which escaped again after meeting water molecules, plankton, sediment and dissolved material.
Weather
How clouds stay aloft while holding water
Gravity never switches off inside a cloud. Its droplets remain overhead because they are extraordinarily small, fall slowly through air and live inside a constantly moving system.
Space
Why some eclipses leave a ring of fire
A nearly perfect alignment can still leave sunlight around the Moon. The deciding detail is not the Moon’s true size, but how large it appears from Earth.
Oceans
Life powered by chemistry at hydrothermal vents
Far below sunlight, seawater circulates through hot rock and returns carrying chemical fuel. Microbes turn the resulting reactions into an ecosystem.
Weather
Why some places get far more lightning
A lightning map is also a map of heat, moisture, rising air and terrain. The ingredients are widespread, but geography assembles them very unevenly.
Oceans
How ocean currents move heat
The ocean does not merely store solar energy. Winds, rotating basins and density differences carry it across latitudes and exchange it with the atmosphere.
Space
Why eclipses do not happen every month
New and full moons happen with clocklike regularity. Eclipses need one more coincidence: the Moon must also be crossing the plane of Earth’s orbit.
Oceans
How tiny animals build coral reefs
A reef is not a single organism or a pile of dead rock. It is a living construction site where growth, cementing and erosion never stop.
Weather
Sprites and blue jets: electrical flashes above storms
Lightning is not confined beneath a cloud. Brief red and blue discharges can reach upward through atmospheric layers most storms never touch.
Oceans
Why a tsunami is not an ordinary wave
A tsunami can cross an ocean almost unnoticed, then drive water far inland. Its extraordinary behaviour begins with the amount of ocean set in motion.
Space
How we learned to predict eclipses
Predicting a darkened Sun is one problem. Saying exactly where its shadow will fall requires a clock, a moving planet and even the mountains on the Moon.
Oceans
The organisms that make the sea glow
A blue flash in a breaking wave is a biological event. Beneath the surface, living light can attract a meal, announce danger or conceal its maker.
Weather
Lightning rods: a history of protection
The small metal point on a roof is only the visible beginning of a much larger idea: give a dangerous discharge a controlled route.
Oceans
Life under extraordinary ocean pressure
A fragile-looking animal can live where an air-filled chamber needs a strong hull. The difference begins with what is inside.
Space
Why the eclipsed Moon can turn red
Earth blocks the Sun, yet a little sunlight finds a curved, colourful route through our atmosphere.
Oceans
Why the sea rises and falls
The Moon sets a rhythm, the Sun changes its strength, and every coastline gives the tide a different response.
Space
How the Moon can hide the Sun
A small world can conceal a star when distance supplies the right perspective. The brief darkness can reveal what daylight hides.
Weather
Why thunder arrives after lightning
The pause is a travel time. The rolling sound is a clue to the shape of the flash and the atmosphere carrying its voice.
Weather
Before the flash: how a storm builds lightning
The bolt lasts an instant. Its preparation takes a cloud full of moving ice, separated charges and air pushed beyond its insulating limits.
Oceans
Why seawater is salty and rivers mostly are not
The sea keeps a chemical record of rain on rocks, water returning to the sky and reactions beneath the ocean floor.
Technology
How undersea cables carry the internet
A message crosses the world in a moment. Its journey began with a ship, a copper wire, and an ocean of uncertainty.
Deeper reading
How does light stay inside a glass fibre?
A closer look at the boundary that turns a strand of glass into a path for information.
Deeper reading
Why faster broadband does not remove every delay
More information per second and a shorter wait are two different improvements.